(Not advice but a relevant point to prevent needless problems through no fault of passengers)
There is surely an internal system for logging such instances e.g. TVM faults/ a member of staff rings in sick and the ticket office isn't opened at the usual time (am sure there's a history/log of each TVM and any faults kept).
However problems with ticket vending machines and ticket offices ought to be publically displayed on the website (possibly as part of the NTA contractual requirement). Have never seen any such info ever posted on the Irish Rail website - have seen info on lifts out of action and the like.
A glance at a website in Britain shows the sort of thing:
http://www.journeycheck.com/northernrail
Hartlepool Facilities: Ticket Vending Machine problem
At Hartlepool station.
The ticket vending machines are out of order.
Message Received :01/02/2013 08:29